Answer:
x = √35
Explanation:
Please see attached photo for explanation.
We'll begin calculating the value of y. This can be obtained as follow:
10² = y² + 4²
100 = y² + 16
Collect like terms
100 – 16 = y²
84 = y²
Take the square root of both side
y = √84
Finally, we shall determine the value of x. This can be obtained as follow:
y² = x² + 7²
(√84)² = x² + 49
84 = x² + 49
Collect like terms
84 – 49 = x²
35 = x²
Take the square root of both side
x = √35